import java.util.*;
/**
*
* Source : https://oj.leetcode.com/problems/anagrams/
*
* Created by lverpeng on 2017/7/18.
*
* Given an array of strings, group anagrams together.
*
* For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"],
* Return:
*
* [
* ["ate", "eat","tea"],
* ["nat","tan"],
* ["bat"]
* ]
*
* Note:
*
* For the return value, each inner list's elements must follow the lexicographic order.
* All inputs will be in lower-case.
*
* Update (2015-08-09):
* The signature of the function had been updated to return list<list<string>> instead
* of list<string>, as suggested here. If you still see your function signature return
* a list<string>, please click the reload button to reset your code definition.
*
*/
public class GroupAnagram {
public List<String[]> anagram (String[] strArr) {
List<String[]> result = new ArrayList<String[]>();
Map<String, List<Integer>> map = new HashMap<String, List<Integer>>();
for (int i = 0; i < strArr.length; i++) {
char[] charArr = strArr[i].toCharArray();
Arrays.sort(charArr);
String str = new String(charArr);
if (map.keySet().contains(str)) {
map.get(str).add(i);
} else {
List<Integer> list = new ArrayList<Integer>();
list.add(i);
map.put(str, list);
}
}
for (Map.Entry<String, List<Integer>> entry : map.entrySet()) {
String[] strs = new String[entry.getValue().size()];
int index = 0;
for (Integer i : entry.getValue()) {
strs[index] = strArr[entry.getValue().get(index)];
index ++;
}
Arrays.sort(strs);
result.add(strs);
}
return result;
}
public static void printList (List<String[]> list) {
for (String[] strs : list) {
System.out.println(Arrays.toString(strs));
}
System.out.println();
}
public static void main(String[] args) {
GroupAnagram groupAnagram = new GroupAnagram();
printList(groupAnagram.anagram(new String[]{"eat", "tea", "tan", "ate", "nat", "bat"}));
}
}